chore: add unreceived packets rpc

modules/core/04-channel/v2/client/cli/cli.go

@@ -25,6 +25,7 @@ func GetQueryCmd() *cobra.Command {
 		getCmdQueryPacketCommitments(),
 		getCmdQueryPacketAcknowledgement(),
 		getCmdQueryPacketReceipt(),
+		getCmdQueryUnreceivedPackets(),
 	)
 
 	return queryCmd

modules/core/04-channel/v2/client/cli/query.go

@@ -14,6 +14,10 @@ import (
 	"github.com/cosmos/ibc-go/v9/modules/core/exported"
 )
 
+const (
+	flagSequences = "sequences"
+)
+
 // getCmdQueryChannel defines the command to query the channel information (creator and channel) for the given channel ID.
 func getCmdQueryChannel() *cobra.Command {
 	cmd := &cobra.Command{
@@ -282,3 +286,45 @@ func getCmdQueryPacketReceipt() *cobra.Command {
 
 	return cmd
 }
+
+func getCmdQueryUnreceivedPackets() *cobra.Command {
+	cmd := &cobra.Command{
+		Use:   "unreceived-packets [channel-id]",
+		Short: "Query a channel/v2 unreceived-packets",
+		Long:  "Query a channel/v2 unreceived-packets by channel-id and sequences",
+		Example: fmt.Sprintf(
+			"%s query %s %s unreceived-packet [channel-id] --sequences=1,2,3", version.AppName, exported.ModuleName, types.SubModuleName,
+		),
+		Args: cobra.ExactArgs(1),
+		RunE: func(cmd *cobra.Command, args []string) error {
+			clientCtx, err := client.GetClientQueryContext(cmd)
+			if err != nil {
+				return err
+			}
+
+			channelID := args[0]
+			seqSlice, err := cmd.Flags().GetInt64Slice(flagSequences)
+			if err != nil {
+				return err
+			}
+
+			seqs := make([]uint64, len(seqSlice))
+			for i := range seqSlice {
+				seqs[i] = uint64(seqSlice[i])
+			}
+
+			queryClient := types.NewQueryClient(clientCtx)
+			res, err := queryClient.UnreceivedPackets(cmd.Context(), types.NewQueryUnreceivedPacketsRequest(channelID, seqs))
+			if err != nil {
+				return err
+			}
+
+			return clientCtx.PrintProto(res)
+		},
+	}
+
+	cmd.Flags().Bool(flags.FlagProve, true, "show proofs for the query results")
+	flags.AddQueryFlagsToCmd(cmd)
+
+	return cmd
+}

modules/core/04-channel/v2/keeper/grpc_query.go

@@ -187,3 +187,56 @@ func (q *queryServer) PacketReceipt(ctx context.Context, req *types.QueryPacketR
 
 	return types.NewQueryPacketReceiptResponse(hasReceipt, nil, clienttypes.GetSelfHeight(ctx)), nil
 }
+
+// UnreceivedPackets implements the Query/UnreceivedPackets gRPC method. Given
+// a list of counterparty packet commitments, the querier checks if the packet
+// has already been received by checking if a receipt exists on this
+// chain for the packet sequence. All packets that haven't been received yet
+// are returned in the response
+// Usage: To use this method correctly, first query all packet commitments on
+// the sending chain using the Query/PacketCommitments gRPC method.
+// Then input the returned sequences into the QueryUnreceivedPacketsRequest
+// and send the request to this Query/UnreceivedPackets on the **receiving**
+// chain. This gRPC method will then return the list of packet sequences that
+// are yet to be received on the receiving chain.
+//
+// NOTE: The querier makes the assumption that the provided list of packet
+// commitments is correct and will not function properly if the list
+// is not up to date. Ideally the query height should equal the latest height
+// on the counterparty's client which represents this chain.
+func (q *queryServer) UnreceivedPackets(ctx context.Context, req *types.QueryUnreceivedPacketsRequest) (*types.QueryUnreceivedPacketsResponse, error) {
+	if req == nil {
+		return nil, status.Error(codes.InvalidArgument, "empty request")
+	}
+
+	if err := host.ChannelIdentifierValidator(req.ChannelId); err != nil {
+		return nil, status.Error(codes.InvalidArgument, err.Error())
+	}
+
+	_, found := q.GetChannel(ctx, req.ChannelId)
+	if !found {
+		return nil, status.Error(
+			codes.NotFound,
+			errorsmod.Wrapf(types.ErrChannelNotFound, "channel-id %s", req.ChannelId).Error(),
+		)
+	}
+
+	var unreceivedSequences []uint64
+	for i, seq := range req.Sequences {
+		// filter for invalid sequences to ensure they are not included in the response value.
+		if seq == 0 {
+			return nil, status.Errorf(codes.InvalidArgument, "packet sequence %d cannot be 0", i)
+		}
+
+		// if the packet receipt does not exist, then it is unreceived
+		if _, found := q.GetPacketReceipt(ctx, req.ChannelId, seq); !found {
+			unreceivedSequences = append(unreceivedSequences, seq)
+		}
+	}
+
+	selfHeight := clienttypes.GetSelfHeight(ctx)
+	return &types.QueryUnreceivedPacketsResponse{
+		Sequences: unreceivedSequences,
+		Height:    selfHeight,
+	}, nil
+}

modules/core/04-channel/v2/types/query.go

@@ -84,3 +84,11 @@ func NewQueryPacketReceiptResponse(exists bool, proof []byte, height clienttypes
 		ProofHeight: height,
 	}
 }
+
+// NewQueryPacketReceiptRequest creates and returns a new packet receipt query request.
+func NewQueryUnreceivedPacketsRequest(channelID string, sequences []uint64) *QueryUnreceivedPacketsRequest {
+	return &QueryUnreceivedPacketsRequest{
+		ChannelId: channelID,
+		Sequences: sequences,
+	}
+}